JP5551083B2 - Pressure sensitive adhesive with adhesive strength with excellent temperature stability - Google Patents

Abstract

Adhesive composition crosslinked by heating, comprises a polyurethane (20-85%) comprising two hydrolysable alkoxysilane type terminal groups (I), a compatible tackifying resin (15-80%) having an average molar mass of 200 Da-5 kDa, where the resin is obtained by: polymerizing terpene hydrocarbons in the presence of Friedel-Crafts catalyst and the reaction with phenols; and polymerizing alpha-methyl styrene and optionally reaction with phenols, and a crosslinking catalyst (0.01-3%). Adhesive composition crosslinked by heating, comprises a polyurethane (20-85%) comprising two hydrolysable alkoxysilane type terminal groups, of formula ((R 5>O) 3-p(R 4>) pSi-R 3>-NH-C(=O)-(OR 2>) n-(O-C(=O)-NH-R 1>-NH-C(=O)-(OR 2>) n) m-O-C(=O)-NH-R 3>-Si(R 4>) p(OR 5>) 3-p) (I), a compatible tackifying resin (15-80%) having an average molar mass of 200 Da-5 kDa, where the resin is obtained by: polymerizing terpene hydrocarbons in the presence of Friedel-Crafts catalyst and the reaction with phenols; and polymerizing alpha-methyl styrene and optionally reaction with phenols, and a crosslinking catalyst (0.01-3%). R 1> : aromatic or aliphatic 1-15C divalent hydrocarbon; R 2> : 1-4C divalent alkylene; R 3> : 1-3C divalent alkylene; R 4>, R 5> : 1-4C alkyl; n : integer such that the average molar mass in polyether block (-(OR 2>) n) is 300 Da-30 kDa; m : integer such that the average molar mass in (I) is 600 Da-60 kDa; and p : 0-2. An independent claim is included for a self-adhesive support obtained by preheating the adhesive composition at a temperature of 50-130[deg] C, coating the heated composition on a support layer and then crosslinking by heating the coated support at a temperature of 50-150[deg] C.

Description

  The present invention relates to a heat-curable self-adhesive composition and a self-adhesive support coated with a pressure-sensitive adhesive obtained by curing the composition. This self-adhesive support is used to produce self-adhesive labels and / or tapes and has the advantage that it can maintain adhesive strength over a wide range of temperatures.

  A pressure sensitive adhesive (PSA) is a substance that instantly provides tackiness to a substrate coated with it at room temperature under only slight pressure. This PSA is widely used in the manufacture of self-adhesive labels for imparting information (eg, barcodes, instructions, prices) and / or decoration to articles. PSA is also used in the manufacture of various self-adhesive tapes. For example, in addition to transparent adhesive tapes that are widely used on a daily basis, cardboard packaging materials are formed / assembled, surface protection in painting operations, electrical cable retention in construction and transportation, carpets with double-sided adhesive tape Is used in combination.

  In the production of self-adhesive labels and / or tapes, a continuous coating process is generally used to apply a predetermined amount (typically g / m2) of PSA to the entire surface of a large sized support (printable support if necessary). Applied). This amount will hereinafter be represented by the term “weight per unit area”. The support layer is composed of a paper or polymer material film having one or more layers. The adhesive layer itself covering the support layer is covered with a protective layer (called a release liner) made of, for example, a silicon-coated film. The multilayer system thus obtained is generally wound on a large reel up to 1 m in diameter and 2 m in width, packaged, stored and transported.

  A self-adhesive label is then made from this multilayer system and cut to the desired shape and dimensions, and then the desired decorative elements and / or information are printed on the printable surface on the support layer to the end user. Supplied. The protective layer can be easily removed and the adhesive layer remains fixed on the support layer. After separating the protective layer, the label is applied onto the article to be coated using a labeling machine on a manual or automatic packaging line. Further, the multi-layer system can be cut into a predetermined width and length and packaged as a roll to form a self-adhesive tape.

  Since PSA is highly tacky at room temperature, self-adhesive labels and / or tapes are on the substrate (or article) to be coated, for example, on the bottle or the like on the label, on the packaging box to be formed on the tape. Can be bonded quickly at high industrial production rates.

  In some PSA applications, the adhesive strength of the label and / or tape on the substrate is maintained even when the adhesive portion (and thus the article coated with the label and / or tape) is exposed to a wide range of temperature changes. There are areas where it is desirable to be done. Examples include spreading materials on certain automotive components located near the engine, packaging materials that must receive heated hot liquid during packaging, and labeling hot at the end of the production line. And articles (for example, tires) that must be marked. In addition, self-adhesive tape for assembly of parts requiring heat resistance, for example, aircraft and other vehicle interiors.

  PSA widely used in this field includes high molecular weight acrylate type polymers (or copolymers). The polymer is in the form of an aqueous emulsion or organic solution. However, the operation of coating this type of PSA on a support is complicated from an industrial revision, requiring an additional step to dry the emulsion, and industrial safety and health issues against evaporation of organic solvents. Requires specific equipment that takes into account. Furthermore, the disadvantages associated with the unpleasant odor of polyacrylates must also be taken into account.

  Since PSA does not contain solvent or water, hot melt pressure sensitive adhesive or HMPSA is a solid material at room temperature and is applied (or coated) on a support in a molten state, and has high adhesion on various substrates after cooling. Degrees and adhesion strength. However, since the corresponding composition generally comprises a thermoplastic polymer, the bond providing support to the substrate is at high temperature and exhibits all of the cohesive forces required for the pre-targeted application area. Absent.

  Patent Document 1 (US Pat. No. 6,486,229) discloses a UV comprising a tackifying resin, a photopolymerization initiator, and a radial multi-block butadiene styrene copolymer (the butadiene block has a high content of pendant vinyl groups). A curable hot melt adhesive composition is described. This composition is coated on a support in a state before being cured, and is cured by irradiation with ultraviolet rays. The self-adhesive support thus obtained is particularly suitable for tape and label applications that require excellent cohesion at high temperatures.

  Patent Document 2 (International Patent Publication WO 2004/011559) describes a coating acrylic composition comprising an acrylic copolymer, a photopolymerization initiator, and a polyfunctional (meth) acrylate. This composition is also cured by irradiation with ultraviolet light to become a high-performance PSA.

However, these methods of manufacturing PSA have industrial health problems due to UV lamps and cost disadvantages due to short lamp usage times. Furthermore, in the case of a self-adhesive support in which the weight per unit area of PSA is increased (for example, when the weight per unit area is 70 g / m ² or more), the adhesive strength should be reliably maintained in a wide temperature range, particularly at high temperatures. Is difficult.

  Patent Document 3 (European Patent No. EP 0106330) includes a tackifying resin having a silylhydrolysable (hydrolyzable) end group and a polyether, and has excellent heat resistance and adhesiveness characteristics. A composition is described. This patent also describes a method for producing a pressure sensitive adhesive product by applying the above composition onto a support. The composition is charged with a catalyst and cured at a temperature between room temperature and 150 ° C.

Patent Document 4 (Canadian Patent No. CA 2554743) discloses a tackifier resin, a catalyst, and an oxy group having a silyl hydrolysable (hydrolyzable) silyl group of 0.3 to 0.7 equivalents having a molecular weight of 1,500 to 100,000. A composition comprising an alkylene polymer is described. This composition is applied onto a support by a coating machine and cured at high temperature to form a self-adhesive product.
However, the self-adhesive products described in the latter two patents have the disadvantage that when the weight per unit area increases, the adhesion strength on the substrate at high temperatures becomes insufficient.

US Patent No. US 6486229 International Patent Publication No. WO 2004/011559 European Patent No. EP 0106330 Canadian Patent No. CA 2554743

An object of the present invention is to provide a thermosetting pressure-sensitive adhesive composition that exhibits excellent adhesive strength and tackiness (tack) after being coated on a support and cured.
Another object of the present invention is to obtain an adhesive seam (which can be obtained by attaching the above self-adhesive support to a substrate) that can maintain the required cohesive force in a wide temperature range even when the weight per unit area of the PSA is increased. To be provided).

（ここで、
Ｒ¹は５〜１５の炭素原子数を有する芳香族または脂肪族の直鎖または分岐鎖または環状の炭化水素をベースにした２価の基を表し、
Ｒ²は１〜４の炭素原子数を有する直鎖または分岐鎖の２価のアルキレン基を表し、
Ｒ³は１〜３の炭素原子数を有する直鎖の２価のアルキレン基を表し、
Ｒ⁴とＲ⁵は各々１〜４の炭素原子を有する直鎖または分枝鎖のアルキル基を表し、互いに同一でも異なっていてもよく、複数のＲ⁴（またはＲ⁵）が存在する場合にはそれらは互いに同一でも異っていてもよく、
ｎは式−［ＯＲ²］ｎ−のポリエーテルブロックの数平均分子量が３００Ｄａ〜３０ｋＤａの間になるような整数であり、
ｍは式（Ｉ）のポリマーの数平均分子量が６００Ｄａ〜６０ｋＤａとの間になるような整数であり、
ｐは０、１または２の整数である）
（２）１５〜８０重量％の下記（ｉ）または（ｉｉ）で得られる樹脂の中から選択される２００Ｄａ〜５ｋＤａの間の数平均分子量を有する相溶性のある粘着付与樹脂：
（ｉ）フリーデル−クラフッ触媒の存在下でのテルペン炭化水素とフェノールとの重合、
（ｉｉ）α−メチルスチレン重合（必要に応じてフェノールと反応させてもよい）、
（３）０．０１〜３重量％の硬化触媒。 The first object of the present invention is a thermosetting adhesive composition comprising the following (1) to (3):
(1) 20 to 85% by weight of polyurethane having two hydrolysable alkoxysilane-type end groups having the following formula (I):

(here,
R ¹ represents a divalent group based on an aromatic or aliphatic linear, branched or cyclic hydrocarbon having 5 to 15 carbon atoms;
R ² represents a linear or branched divalent alkylene group having 1 to 4 carbon atoms,
R ³ represents a linear divalent alkylene group having 1 to 3 carbon atoms,
R ⁴ and R ⁵ each represents a linear or branched alkyl group having 1 to 4 carbon atoms, which may be the same or different from each other, and when a plurality of R ⁴ (or R ⁵ ) are present. They may be the same or different from each other,
n is an integer such that the number average molecular weight of the polyether block of formula — [OR ² ] n— is between 300 Da and 30 kDa,
m is an integer such that the number average molecular weight of the polymer of formula (I) is between 600 Da and 60 kDa,
p is an integer of 0, 1 or 2)
(2) A compatible tackifying resin having a number average molecular weight between 200 Da and 5 kDa selected from 15 to 80% by weight of the resin obtained in the following (i) or (ii):
(I) polymerization of terpene hydrocarbons with phenol in the presence of Friedel-Craft catalyst,
(Ii) α-methylstyrene polymerization (may be reacted with phenol if necessary),
(3) 0.01 to 3 wt% curing catalyst.

Unless stated otherwise herein, the amounts expressed in percentage form correspond to weight / weight percentages, the groups R ^{1 to} R ⁵ and the integers n, m and p are as defined above for each chemical formula. The number average molecular weight and weight average molecular weight, which have the same meaning and expressed in daltons (da), were determined by column gel permeation chromatography calibrated with polyethylene glycol (PEG) standards.

The polymer of formula (I) contained in the composition of the present invention can be obtained by the following method.
In the first step, formula (II) with two hydroxyl end groups:

Polyurethane) is prepared by reacting 1 mole of diisocyanate of formula (III) with about 2 moles of polyether diol of formula (IV):
NCO-R ¹ -NCO (III)
^{H- [OR 2] n-OH} (IV)
(This corresponds to an NCO / OH functional group ratio of about 0.5)

The reaction is carried out at a temperature of 60 to 90 ° C. for about 2 to 8 hours, optionally in the presence of a catalyst.
In the second step, the polyurethane of formula (II) is converted to a polyurethane of formula (I) by a silylation reaction with an isocyanate silane of formula (V):
^{NCO-R 3 -Si (R 4} ) p (OR5) 3-p (V)
The amount of polyurethane of formula (II) is about 1 mole per 2 moles of compound of formula (V).

  Polyether diols of formula (IV) and isocyanate silanes of formula (V) are commercially available. For example, γ-isocyanate-n-propyltrimethoxysilane is Wacker as Geniosil® GF 40, and α-isocyanate-n-methyl (methyl) dimethoxysilane is Wacker as Geniosi® XL 42 (Wacker) is commercially available.

  The above two synthesis steps are carried out under anhydrous conditions to avoid hydrolysis of alkoxysilane groups. A typical temperature range for carrying out these reactions is 30-120 ° C, in particular 60-90 ° C. There is no particular problem with slight variations from the stoichiometry described above, but in the first step (synthesis of the polyurethane of formula II) the variation should not exceed 10% and the second step (of the polyurethane of formula I) In synthesis) the variation must not exceed 2%.

The details of the method for producing the polyurethane of the formula (I) having an alkoxysilane type end group can be referred to the following documents.
European Patent No. EP 0 931 800

  The number average molecular weight of the polyurethane of formula (I) is between 600 Da and 60 kDa. This corresponds to the value of m being about 1-10.

In one preferred variant of the composition according to the invention, the polyurethane block of formula (I) has a number average molecular weight of 4 to 50 kDa (which corresponds substantially to a value of m of 1 to 4). , - {number average molecular weight of OR ^2] n-is between 2～25KDa.

In another preferred variant of the invention, which can be combined with the variant described above, the polyurethane of formula (I) is:
R ¹ is selected from one of the following divalent groups (the formula has the following two free valences):

R ² is a divalent group of ethylene and / or isopropylene;
R ³ is a divalent group of methylene and / or n-propylene,
R ⁴ and R ⁵ each represents a methyl or ethyl group radical.

In another particularly preferred variant of the composition according to the invention, the polyurethane of formula (I) is:
R ¹ is a divalent group of the following formula derived from isophorone:

R ² is a divalent group of isopropylene,
R ³ is a divalent group of n-propylene,
_{^{-Si (R 4) p (OR}} 5) 3-p group is a trimethoxysilyl group.

  An advantageous variant of the PSA according to the invention is that the polyurethane of formula (I) has a polydispersity index between 1.1 and 2.0. This polydispersity index is the ratio of the weight average molecular weight to the number average molecular weight. This polyurethane can be produced from a polyether diol of formula (IV) having a polydispersity index of 1 to 1.6. Such polyethers can be obtained by polymerizing the corresponding alkylene oxides in a known manner in the presence of catalysts based on metal-cyanide double complexes.

When R ² is an isopropylene group, the polydispersity index of the polyurethane of formula (I) is advantageously between 1.3 and 1.6. This polyurethane can be produced from polyisopropoxydiol (also called polypropylene glycol or polyoxyisopropenol) having a polydispersity index (1 to 1.4). This polypropylene glycol is commercially available. An example of a polypropylene glycol having a polydispersity index of about 1.1 is commercially available as ACCLAIMR® from Bayer. For example, ACCLAIMR (registered trademark) 8200 having a number average molecular weight of about 8250 Da, ACCLAIMR (registered trademark) 12200 having a number average molecular weight of 11225 Da, ACCLAIMR (registered trademark) 18200 having a number average molecular weight of 18100 Da, and the like.

The expression that the tackifying resin contained in the composition of the present invention is a “compatible tackifying resin” is substantially uniform when mixed with the polymer of formula (I) at a ratio of 50% / 50%. It means a tackifying resin that becomes a mixture. This resin is commercially available and can be obtained by the methods (i) and (ii) above. Examples include the following products:
Method (i) :
Dertophene® 1510 having a molecular weight Mn of about 870 Da available from DRT, Dertophene® H150 having a molecular weight Mn of about 630 Da, Sylvarez available from Arizona Chemical Co. having a molecular weight Mn of about 1200 Da Registered trademark) TP 95
Method (ii) :
Norsolene® Wl00 having a number average molecular weight of 900 Da available from Clay Valley, obtained by polymerization of α-methylstyrene without the action of phenol, or about 1740 Da obtained in a production process involving the action of phenol Sylvarez® 510 available from Arizona Chemical Company with a molecular weight Mn of

  The tackifying resin used in one preferred variant of the heat curable adhesive composition of the present invention can be obtained by method (i).

  The curing catalyst that can be used in the composition of the present invention can be any catalyst known to those skilled in the art as silanol condensation. Examples include organic derivatives of titanium, such as titanium acetylacetonate (commercially available from DuPont under the trade name TYZOR® AA75), organic derivatives of aluminum, such as aluminum chelates (K-KAT® from King Industries) 5218), amines such as 1,8-diazobicyclo [5.4.0] undec-7-ene or DBU.

  In a preferred embodiment of the thermoset adhesive coarse according to the present invention, the polyurethane of formula (I) is 40-65% by weight and the tackifying resin is 35-60% by weight.

  In addition to the polyurethane having a hydrolyzable end group of the formula (I), the crude of the present invention may optionally be a thermoplastic polymer often used in the production of HMPSA, such as ethylene / vinyl acetate (EVA) or A styrene block copolymer may be further included.

  In addition to the tackifying resin obtained by the above method (i) or (ii), the thermosetting composition of the present invention further includes other tackifying resins having a number average molecular weight of 200 to 5000 Da, alone or in combination. It can also be included. Examples include the following resins:

(iii) Natural or modified rosins such as rosin extracted from pine gum, wood root extracted wood rosin and derivatives thereof such as hydrogenated, dimerized, polymerized or esterified derivatives with polyols such as monoalcohol or glycerin ,
(iv) a resin obtained by hydrogenation, polymerization or copolymerization (with aromatic hydrocarbons) of a mixture of unsaturated aliphatic hydrocarbons having about 5, 9 or 10 carbon atoms derived from petroleum fractions;
(v) a terpene resin obtained by polymerization of a terpene hydrocarbon such as monoterpene (or pinene), generally in the presence of a Friedel-Craft catalyst,
(vi) copolymers based on natural terpenes such as styrene / terpenes, α-methylstyrene / terpenes, vinyl toluene / terpenes,
(vii) Acrylic resin.

  However, the content of such a resin in the composition of the present invention should not exceed 40% by weight of the total weight of tackifying resin present in the composition.

  The thermosetting adhesive composition of the present invention may contain 3% by weight or less of a hydrolyzable alkoxysilane derivative, preferably a trimethoxysilane derivative, as a desiccant. Use of this type of agent can extend the shelf life of the composition of the present invention prior to storage and transportation. An example is γ-methacryloxypropyltrimethoxysilane, a compound available from US Momentive Performance Materials Inc under the trade name SILQUEST® A-74.

  The compositions of the present invention include plasticizers such as phthalates or benzoates, paraffin oils, naphthenic oils (eg, Prisol® 352 from ESSO) and polyethylene homopolymer waxes (Honeywell's .A-C®). ) 617) or polyethylene / vinyl acetate copolymer waxes, pigments, dyes or fillers.

  The composition of the present invention preferably further comprises 0.1 to 2% by weight of one or more stabilizers (or antioxidants). This compound is introduced to protect the composition of the present invention from deterioration due to reaction with oxygen caused by the action of heat or light. This compound contains a major antioxidant that scavenges free radicals, and is a substituted phenol such as Irganox® 1076 from CIBA. The main component antioxidant can be used alone or in combination with other secondary antioxidants or UV stabilizers.

The thermosetting adhesive composition of the present invention can be produced by the following method:
(1) an air-free atmosphere at a temperature of 50 to 170 ° C., preferably 100 to 170 ° C., preferably a step of mixing in an inert atmosphere, with the polymer of formula (I) having
(2) a step for cooling the resulting mixture to a temperature of 50-90 ° C, preferably about 70 ° C;
(3) A step that incorporates a catalyst, optionally a desiccant and other optional ingredients into the mixture.

Another subject of the invention is a self-adhesive support obtained by the following method:
(A) preheating the adhesive composition as defined above to a temperature of 50-130 ° C;
(B) apply it on the support layer,
(C) The coated support is cured by heating to a temperature of 50 to 150 ° C.

The step (b) for coating the support layer can be carried out using a known coating device such as a lip die or curtain coating type die, roller. The weight per unit area of the adhesive composition to be used is 3 to 500 g / m ² , preferably 10 to 250 g / m ² . Materials that can be used for the support layer are, for example, one or more layers of paper or a film of polymeric material.

  The time required for the curing of the stairs (c) can be varied within a large range, for example between 1 second and 10 minutes. In this heating and curing step, a three-dimensional polymer network is formed by the action of moisture in the atmosphere of the polyurethane polymer chains of formula (I) and siloxane-type bonds. Accordingly, the cured adhesive composition is a pressure sensitive adhesive and imparts the desired adhesive strength and tackiness (tack) to the support layer on which it is applied.

Therefore, a polyethylene terephthalate (PET) support coated with a weight per unit area of 20 g / m ² is permanently bonded to a stainless steel substrate, and its adhesive strength (measured by a 180 ° peel test on stainless steel, described later) Corresponds to 1-15 N / cm, preferably 2-10 N / cm. The adhesion of the same support (measured by a loop adhesion test described later) is between 0.5 and 8 N / cm ² at room temperature, preferably ² to 6 N / cm ² .

Similarly, a polyethylene terephthalate (PET) support coated with a weight per unit area of 200 g / m ² is permanently bonded, and the adhesive strength corresponds to 1 to 50 N / cm, preferably 5 to 30 N / cm. Tack of this same support 1~30N / cm ² at room temperature, preferably 4~15N / cm ^2.

  The adhesive seam formed by attaching the support layer coated with the cured composition above onto the substrate securely attaches the support layer in the temperature range of −60 ° C. to + 200 ° C.

  The self-adhesive support of the present invention can have a non-tacky protective layer covering the PSA layer, and this protective film can simply be laminated.

  The invention further relates to the use of a self-adhesive support as defined above in the production of self-adhesive labels and / or tapes.

Weight per unit area of the heat curable adhesive composition required for the production of self-adhesive labels 1 to 100 g / m ^2, preferably 20 to 50 g / m ^2. 3~500g / m ² of required for the preparation of self-adhesive tape, preferably 15~250g / m ^2.

Hereinafter, examples of the present invention will be described, but the present invention should not be construed as being limited to the formula examples.
Examples A to C are examples of methods for preparing polyurethanes of formula (I), where the two -alkoxysilane-type end groups consist of trimethoxysilyl groups, R ² is an isopropylene group, and R ³ is n- Propylene group.

Example A
Preparation of polyurethane A of formula (I) in which the molecular weight of the polyether block of formula- [OR ² ] n- is about 8250 Da :
In a glass reactor, 961.2 g (0.1165 mol) polyisopropoxydiol ACCLAIM® 8200 and 12.99 g (0.0582 mol) isophorone diisocyanate (IIPDI) (this is the ratio of NCO / OH functional groups = 0.5) And 120 ppm bismuth / zinc neodecanoate type catalyst (commercially available from Borchers under the name Borchi Kat VP 0244).
The mixture was kept under nitrogen for 3 hours at 85 ° C. with constant stirring until the NDI functionality of IPDI was completely reacted. To the resulting polyurethane with hydroxyl end groups, 24.6 g (0.1165 mol) of γ-isocyanate-n-propyltrimethoxysilane is added and the mixture is maintained at 85 ° C. until the NCO functionality has completely disappeared. The obtained polyurethane A has a viscosity of 55 Pa.s. having a viscosity of s (measured using a Brookfield viscometer with a No. 7 spindle speed of 20 revolutions per minute at 23 ° C.), a number average molecular weight of about 20 kDa and a polydispersity of about 1.3 With an index.

Example B
Preparation of polyurethane B of formula (I) in which the polyether block of formula- [OR ² ] n- has a molecular weight of about 11225 Da The procedure of Example A was repeated but 1100 g (0.098 mol) of polyisopropoxydiol ACCLAIM ( (Registered trademark) 12200 and 10.9 g (0.049 mol) of IPDI (which corresponds to the ratio of the number of NCO / OH functional groups = 0.5) were introduced into a glass reactor, and the resulting polyurethane having hydroxyl-end groups was introduced into the polyurethane. 20.7 g (0.098 mol) of γ-isocyanate-n-propyltrimethoxysilane was added. The obtained polyurethane B had a viscosity of 185 Pa. s (measured under the same conditions as described above), a number average molecular weight of about 30 kDa, and a polydispersity index of about 1.4.

Example C
Preparation of polyurethane B of formula (I) in which the polyether block of formula- [OR ² ] n- has a molecular weight of about 18100 Da The procedure of Example A was repeated but with 1220 g (0.0685 mol) of polyisopropoxydiol ACCLAIM ( (Registered trademark) 18200 and 7.03 g (0.0342 mol) IPDI (which corresponds to the ratio of the number of NCO / OH functional groups = 0.5) were introduced into a glass reactor, and 14.45 was added to the polyurethane having hydroxyl-end groups. g (0.0685 mol) of γ-isocyanate-n-propyltrimethoxysilane was added. The obtained polyurethane C was 390 Pa.s. s (measured under the same conditions as described above), a number average molecular weight of about 40 kDa, and a polydispersity index of about 1.5.

Example 1
1) Production of heat-curable adhesive composition based on polyurethane A The composition described in [Table 1] below was placed in a glass reactor. First, a tackifying resin (Dertophene® 1510) is introduced under reduced pressure and heated at about 160 ° C. and polyurethane A is added after the resin has completely melted. The mixture is stirred under reduced pressure for 15 minutes and then cooled to 70 ° C. Then, a desiccant (SILQUEST® A-174) and a catalyst (K-KAT® 5218) are introduced.
The mixture is maintained under reduced pressure and stirring is continued for an additional 10 minutes. Using a Brookfield viscometer (with a heating system for the purpose of measuring high temperature viscosity), the viscosity of the mixture at 100 ° C. was determined at an A29 spindle speed of 10 rpm. The results (expressed in Pa.s) are shown in [Table 1].

2) Production of two PET support layers coated with two cured compositions with a weight per unit area of 20 and 200 g / m2 Polyethylene terephthalate (PET) with a thickness of 50 μm and dimensions of 20 cm x 40 cm The rectangular sheet was used. Composition obtained in 1)
Preheated to a temperature close to 100 ° C., introduced into the cartridge, from which the beads were extruded and deposited parallel to its width near the edge of the sheet.
The composition contained in the beads was spread so as to form a uniform layer with a substantially constant thickness on the entire surface of the sheet. For this purpose, a film spreader (also called a film applicator) was used and moved from the edge of the sheet to the opposite edge. The weight of unit area of the applied composition layer is 20 g / m ² , which corresponds to a thickness of about 20 μm.

The above operation was repeated with a new PET support layer, and the composition layer was applied so that the weight per unit area was 200 g / m ² . This corresponds to a thickness of about 200 μm.
The two coated PET sheets were placed in a 130 ° C. oven for 5 minutes to cure the composition. Each of the two sheets was laminated with a rectangular siliconized non-tacky protective film having the same dimensions. The following tests were carried out on the two obtained PET support layers.

180 degree peel test on stainless steel plate :
The adhesion strength was evaluated by a 180 peel test on a stainless steel plate using FINAT test method No. 1 described in FINAT Technical Manual, 6th edition, 2001. FINAT is an international association of self-adhesive label manufacturers and converters. The principle of this test is as follows:
Test specimens in the form of rectangular strips (25 mm × 175 mm) are cut from a PET support layer coated with the previously obtained cured composition. This test specimen (after removing the corresponding part of the non-adhesive protective layer) is fixed to a base material made of stainless steel plate for 2/3 or more of its length. The resulting assembly is left at room temperature for 20 minutes. The strip is installed in a tensile tester and peeled off at an angle of 180 degrees at a speed of 300 mm per minute starting from the free end of the rectangular strip. The force required to peel the strip under this condition is measured with a tensile tester.
The results corresponding to the weight per unit area of the ^two samples (20 and 200 g / m ² ) are shown in N / cm in [Table 1].

Tack test (also called loop test) :
Adhesion was evaluated by the loop adhesion test described in F] INAT Method No. 9 based on the following principle: Test in the form of a rectangular strip (25 mm x 175 mm) from a PET support layer coated with a cured composition Cut the specimen. After removing all of the non-stick protective layer, both ends of the strip are joined into a loop. The adhesive layer is on the outside. Both ends are attached to the movable jaw of a tensile tester capable of moving forward and backward along the longitudinal axis at a moving speed of 300 mm / min. First, the lower part of the vertically arranged loop is brought into contact with a horizontal glass plate of 30 mm × 25 mm on the side of a square area having a side of about 25 mm. After making contact, the direction of jaw movement is reversed. The degree of adhesion is the maximum force required to completely peel the loop from the plate.
The results corresponding to the weight per unit area of the ^two specimens (20 and 200 g / m ² ) are shown in N / cm ² in [Table 1].

Durability of bonded seams against static shear at 90 ° C :
The stability of the adhesive strength of the obtained PET support layer at a high temperature was evaluated by a test for determining the durability time of the adhesive seam against a static shear force at 90 ° C. This test was conducted by FINAT method No. 8 using the following principle.
Test specimens in the form of rectangular strips (25 mm × 75 mm) were cut from the two PET support layers described above. After all the non-tacky protective layer is removed, the edge of the adhesive strip is fixed to a glass plate with a square with a side of 25 mm. The resulting test plate is placed substantially vertically in a 90 ° C. oven with a suitable support. A portion of the 50 mm long strip that is not joined is located below the plate. After reaching thermal equilibrium, connect to the free part of the strip with a weight of 1 kg. During the test time, all devices are maintained in an oven at 90 ° C.
Due to the effect of the weight, a shear stress is applied to the adhesive seam that fixes the strip to the plate. This stress is well controlled to place the test plate at an angle of 2 degrees to the vertical.
The time until the strip peels off the plate under this stress and the adhesive seam breaks is measured.
The time was tested on the two samples (weights per unit area 20 and 200 g / m ² ), which was over 24 hours.

Temperature at which the joint seam breaks due to static shear force :
The temperature stability of the adhesive strength of the PET support layer obtained above was evaluated by a test for determining the temperature until the adhesive seam breaks with a static shear force. This test is known as the shear bond breaking temperature (SAFT).
The above test was repeated, but the initial temperature of the oven was set to 20 ° C and the oven heating rate was programmed to 1.6 ° C per minute for both the initial thermal equilibrium test and the test adding 1 kg of weight to the entire device. did.
The temperature at which the strip peels off the plate under this stress and the adhesive seam breaks is measured.
For two samples (weights per unit area of 20 and 200 g / m ² ), this temperature was above 180 ° C.

Examples 2-8
The procedure of Example 1 was repeated with the compositions shown in Table 1. The same results were obtained for both failure of the adhesive seam at elevated temperature with static shear force at 90 ° C. and the durability time of the adhesive seam under static shear force.
The results of the 180 degree peel test and the adhesion test on the stainless steel plate are also shown in [Table 1]. Those whose values were not measured were described as nd.

Claims (10)

(1) and (2) below:
(1) 20 to 85% by weight of polyurethane having two hydrolysable alkoxysilane-type end groups having the following formula (I):

(here,
R ¹ represents a divalent group based on an aromatic or aliphatic linear, branched or cyclic hydrocarbon having 5 to 15 carbon atoms;
R ² represents a linear or branched divalent alkylene group having 1 to 4 carbon atoms,
R ³ represents a linear divalent alkylene group having 1 to 3 carbon atoms,
R ⁴ and R ⁵ each represents a linear or branched alkyl group having 1 to 4 carbon atoms, which may be the same or different from each other, and when a plurality of R ⁴ (or R ⁵ ) are present. They may be the same or different from each other,
n is an integer such that the number average molecular weight of the polyether block of formula — [OR ² ] n— is between 300 Da and 30 kDa,
m is an integer such that the number average molecular weight of the polymer of formula (I) is between 600 Da and 60 kDa,
p is an integer of 0, 1 or 2)
(2) A compatible tackifying resin having a number average molecular weight between 200 Da and 5 kDa selected from 15 to 80% by weight of the resin obtained in the following (i) or (ii):
(I) polymerization of terpene hydrocarbons with phenol in the presence of Friedel-Craft catalyst,
(Ii) α-methylstyrene polymerization (may be reacted with phenol if necessary),
A thermosetting adhesive composition comprising 0.01 to 3 % by weight of a curing catalyst with respect to 100% by weight of Brent . The number average molecular weight of the polyurethane of formula (I) in 4～50KDa, formula - [OR ^2] The adhesive composition of claim 1 the number average molecular weight of the polyether block of n- is located between the 2~25kDa . The adhesive composition according to claim 1 or 2, wherein the polyurethane of formula (I) is:
R ¹ is selected from one of the following divalent groups (the following formula shows two free valences):

R ² is a divalent radical of ethylene and / or isopropylidene Ren,
R ³ is a divalent radical of a methylene and / or n- propylene,
R ⁴ and R ⁵ each represent methyl or ethyl. The adhesive composition according to any one of claims 1 to 3, wherein the polyurethane of formula (I) is:
R ¹ is a divalent group derived from isophorone of the formula:

R ² is a divalent group of isopropylene,
R ³ is a divalent group of n-propylene,
The Si (R ⁴ ) _p (OR ⁵ ) _3-p group is a trimethoxysilyl group. The adhesive composition according to claim 1, wherein the polydispersity index of the polyurethane of the formula (I) in which R ² is an isopropylene group is between 1.3 and 1.6.   The adhesive composition according to any one of claims 1 to 5, wherein the tackifying resin to be used is obtained by the method (i). The adhesive composition according to any one of claims 1 to 6, wherein the Brent comprises 40 to 65% by weight of the polyurethane of the formula (I) and 35 to 60% by weight of a tackifying resin. The adhesive composition according to any one of claims 1 to 6 containing 3% by weight of the hydrolyzable alkoxysilane induction body further as a drying agent with respect to 100 wt% of Brent. Self-adhesive support obtained by the following methods (a) to (c):
(A) preheating the adhesive composition according to any one of claims 1 to 8 to a temperature between 50 and 130 ° C;
(B) applying it onto the support layer;
(C) The coated support is cured by heating to a temperature between 50 and 150 ° C.   Use of the self-adhesive support according to claim 9 in the production of self-adhesive labels and / or tapes.